Newer Drug Seems Better at Controlling Lupus Kidney Complication

WEDNESDAY, Nov. 16 -- A newer immune-suppressing drug called mycophenolate mofetil (CellCept) is better at controlling a serious kidney complication from lupus than another commonly used therapy, a new study suggests.

People taking mycophenolate were about half as likely to progress to treatment failure as were people taking azathioprine (Imuran), according to the researchers.

"This study was looking at maintenance therapy for people with lupus nephritis. Was the older drug azathioprine similar or better to the newer drug mycophenolate mofetil [MMF]? We found that MMF was better overwhelmingly," said study author Dr. Mary Anne Dooley, an associate professor of medicine at the University of North Carolina at Chapel Hill.

"There were fewer flares of recurrent nephritis in the group receiving MMF, and more people on MMF went into complete remission. All of the parameters we looked at were going in the same direction," she said.

Results of the study are published in the Nov. 17 issue of the New England Journal of Medicine.

Systemic lupus erythematosus, or lupus, is an autoimmune disease that can cause problems in many areas of the body, including the kidneys. When lupus affects the kidneys, it's called lupus nephritis.

"Lupus nephritis is one of the more serious consequences of lupus. It's associated with significantly increased morbidity and mortality," explained Dr. Cynthia Aranow, an investigator at the Feinstein Institute for Medical Research in Manhasset, N.Y.

Because lupus is an autoimmune disease, healthy cells are mistakenly destroyed by the body's immune system. So, drugs that suppress the immune system dampen the attack on healthy cells, and are the main treatment currently available for lupus nephritis. The drugs are administered in a similar manner to the way they're used for suppressing the immune system after an organ transplant. The initial phase of treatment includes stronger medicines or stronger doses to induce a remission. Once a remission is induced, patients are switched to maintenance therapy.

And, that's what the current study was designed to assess. It included 227 people with lupus nephritis, ranging in age from 12 to 75 years old. One hundred and sixteen were randomly assigned to maintenance treatment with mycophenolate mofetil and 111 were assigned to receive azathioprine.

Aranow explained that lupus nephritis is classified as an "orphan disease," a term used to describe diseases that affect only small numbers of individuals, which makes getting large numbers of people into clinical trials very difficult.

The researchers found that treatment failure occurred in 32.4 percent of people who were taking azathioprine versus 16.4 percent of those taking mycophenolate mofetil. Flare-ups of kidney disease activity occurred in 23.4 percent of those taking azathioprine and 12.9 percent of those on mycophenolate mofetil, according to the study.

Both groups had significant side effects, including minor infections and gastrointestinal disorders. But, serious adverse events were more common in people taking azathioprine compared to those on mycophenolate -- 33.3 percent versus 23.5 percent, respectively.

The study was initially funded by Aspreva Pharmaceuticals, in collaboration with Roche Pharmaceuticals. Roche produces CellCept, which is U.S. Food and Drug Administration-approved for people who've had an organ transplant. Aspreva's agreement with Roche allowed them to seek approval of CellCept specifically for the treatment of lupus nephritis, according to Dooley. During the course of the study, Aspreva went out of business and was acquired by Vifor Pharmaceuticals. Vifor continued funding the study.

Dooley said that right now mycophenolate mofetil is only available as CellCept, and is more expensive than azathioprine. But, she added, it will soon be generic, which should bring the cost closer to azathioprine.

Aranow said this study shows that "progress is being made, and the prognosis for people with lupus nephritis is better than it was years ago. From this study, it appears that CellCept has a slight superiority over Imuran for keeping lupus nephritis in remission."